Geomembrane lining systems are used for a variety of decorative and containment applications, including ponds for both commercial and residential uses, waterfalls, streams, irrigation canals, storm water retention ponds, agricultural pits and ponds, and aquaculture applications. The wide use of geomembrane lining systems over the alternative liners made of soil, clay, concrete and steel may be attributable to the many advantages of the system over these other available options. These advantages may include secure water containment, enhanced water quality control, cleaning and disinfection capabilities, erosion protection, rapid and easy installation, low maintenance costs, long life and easy repairs.
Geomembrane liners are typically installed with the geomembrane liner extending over the bank of the pond, stream, or other water body, and may extend into a trench that runs along the bank to thereby anchor the liner in place. The anchor portion of the liner acts to ensure that the weight of the water will not pull the geomembrane liner out of its desired position. This installation method results in an exposed portion of the geomembrane liner extending from the water surface over the bank to the point where the liner is buried beneath the earth in the anchor trench.
The exposed portion of the geomembrane liner may either be left exposed or covered with another material. In certain applications the aesthetics of the water body being created are extremely important and therefore it is a necessity that the exposed liner be covered. For example, in applications such as residential ponds or streams, and in water bodies in parks or on golf courses, it is extremely important that the resulting product appear as natural as possible.
In commercial applications such as water treatment facilities and storm water retention ponds, where aesthetics may not be as important, the geomembrane liner is often left uncovered. Even in these types of commercial applications, however, there are advantages to covering the exposed portion of the geomembrane liner.
The exposed portion of a geomembrane liner is subjected to harsh environmental conditions that covered portions of the liner are not. For example, an exposed portion of the liner is subject to UV rays from the sun, wind and flying debris, as well as hail and other precipitation. In addition, the exposed portion of the liner may be punctured, cut or torn by animal claws, teeth, or beaks. In particular, it has been found that birds such as ducks and geese tend to peck at exposed geomembrane liners. It has also been found that large hoofed animals such as deer or cattle can puncture the geomembrane liner when approaching a pond to drink. Another consideration when installing a pond with a geomembrane lining system is the safety of the animals that may drink from or swim in the water body created by the geomembrane liner. The liner can become slippery, and animals that voluntarily enter the water, or animals that fall into the water as a result of the slippery liner, may have trouble getting out of the water and over the bank if the liner is left uncovered.
Current industry practice to cover exposed liners includes covering the exposed liner with large rocks and dirt. Although the rocks and dirt may initially provide adequate coverage of the exposed liner, this solution is often temporary and typically requires maintenance or reapplication after a period of time. The loosely applied rocks have a tendency to shift or slide down the steeper portion of the bank where the exposed geomembrane liner is typically located. Dirt also has a tendency to slide down the bank and will erode over time as well.
Thus, there is a need in the art for a geomembrane lining system having a protective covering over the exposed portion of the geomembrane liner that will not erode or slide down the slope of the bank. There is also a need for a lining system having a protective covering that will provide friction on the surface thereof to permit animals to safely approach, enter, and exit the water body.